Abstract : Evidence was obtained to determineelopment, Washington, D. C. EFFECT OF FOOD INTAKE ON PERFORMANCE CAPABILITIES, by Donald R. Young. 1962, 13p. incl. illus. tables, 18 refs. Unclassified report Presented at the 1962 Army Science Conference, 20-22 June 1962 at the United States Milita y Academy, West Point, New York. DESCRIPTORS: *Food, *Metabolism, Dogs, Nu trition, Re piration, Diet, Water privation, Starvation, Effectiveness. Evidence was obtained to determine that (1) where physical exertion is involved, the body responds best after a period of fasting, but (2) where mental processes are concerned, there is a decrease in efficiency as fasting progresses. Experimental dogs were trained to r n on treadmills and their maximum endurance capacity was measured. The best performance was found in dogs that had been fasting for five days. Additional tests showed that intake of oil, water-soluble vitamins, phospholipids, or cellulose derivatives of natural foods during periods of physical activity reduced endurance capacity 4 %. Dogs were also trained to identify lights and sounds, and their discriminative skill was mea ured over a five day period of food withdrawal. As fasting progressed, the animals became more erratic in problem solving and the probability of error was increased. The test scores show that (1) hunger of 1 to 17 hours duration has no effect on judgment ability, (2) dis rganization of behavior begins after approximately three days of food deprivation, and (3) is particularly marked after five days without food. (Author)